Science

Black Hole V404 Cygni Shows Weaker Magnetic Field Than Once Thought

Scientists have tried to understand black holes ever since their discovery. Their infinite gravity allows them to pull in and devour any planet or other space object that happens to be nearby. Not even light can escape its grasp. Pretty much, it is one of the most fascinating phenomenon in space. Now, scientists have discovered something that could help understand the way the magnetic field around black holes work, and concerning the black hole V404 Cygni.

Black Hole V404 Cygni
insspirito / Pixabay

As you may know, it is said that the area inside and around these massive black holes bends the laws of physics, and that is one of the reasons why it’s risky for close up exploration. They vary in size, though. While some are the size of our Sun or slightly bigger, there are some supermassive black holes, likely located at the center of all huge galaxies in the universe. Moreover, they are thought to be of crucial importance in the way galaxies form and evolve. Black holes are believed to mostly form after the death of huge stars or a merger of neutron stars or when a neutron star collides with another black hole. This emerging is also known for producing gravitational waves.

In new research published in Science by a team of scientists from the University of Florida (UF), it seems that black holes’ magnetic fields might not be as massive as once thought. They were observing the black hole V404 Cygni, which has a distance of 8,000 light years away from Earth. They were measuring the magnetic field surrounding the black hole, and concluded it was 400 times less than previously thought.

So that they could comprehend the way matter acts when exposed to extreme conditions, scientists observed the “jets” of particles which shoot out from the black holes’ magnetic field with a speed close to the speed of light, while other particles get sucked into the black hole.

“The question is, how do you do that?” co-author of the study Stephen Eikenberry, a professor of astronomy in UF’s College of Liberal Arts and Sciences said in a statement on the website. “Our surprisingly low measurements will force new constraints on theoretical models that previously focused on strong magnetic fields accelerating and directing the jet flows. We weren’t expecting this, so it changes much of what we thought we knew.”

The researchers used measurements collected back in 2015, when the black hole had an outburst of those jets, which is rare. They used the 34-foot Gran Telescopio Canarias, which is the world’s biggest telescope, co-owned by UF in Spain’s Canary Islands. The outbursts happen all of the sudden and don’t last long, said the study’s lead author Yigit Dalilar and co-author Alan Garner, doctoral students in UF’s astronomy department. The outbursts of the black hole V404 Cygni from 2015 lasted a couple of weeks, while the same black hole had a similar event which occurred in 1989.

“To observe it was something that happens once or twice in one’s career,” Dalilar said. “This discovery puts us one step closer to understanding how the universe works.”

While black holes’ magnetism may be weaker than previously thought, their gravitational pull is still extreme, confirmed Neil DeGrasse Tyson, director of Hayden Planetarium from the American Museum of Natural History.